Rahu Kalam talks about the period of the day which is considered inauspicious for starting any new and important tasks like marriage, house warming, inauguration, journey, sale, interview or any business. Every day, Rahu Kaal falls on different timings which lasts for 90 minutes.

According to Hindu mythology, Lord Vishnu tricked the demons for the ‘Nectar of immortality’ (Amrit) during the ‘Samudra Manthan’. Meanwhile, a demon named ‘Swarbhanu’ noticed the trap of the Lord Vishnu and appeared in disguise of the god. Although he was suddenly recognised and beheaded by one of the trinity Vishnu, he managed to have a few drops of nectar and became immortal.

The head of the demon became ‘Rahu’ after the incident while the remaining body became ‘Ketu’. Due to the bodiless nature of Rahu, it is considered as a shadow entity who is always unsatisfied and has an obsession of wanting more and more. Rahu is also known to swallow the sun and cause a solar eclipse.

Rahu Kaal is calculated based on the sunrise and sunset timings. As these timings are never the same for any two locations, thus the Rahu Kaal duration and timings vary from place to place. Rahu Kaal is calculated by dividing the time duration between sunrise and sunset into 8 segments. For eg. let the sunrise be at 6:00 am and sunset at 6:00 pm. The difference between them is 12 hours. On dividing these hours into 8 segments, the result is 1.5 hours each. Thus, every day, Raku Kaal shows its effect for 1.5 hours which varies according to the day, muhurat and the sunrise and sunset timings.

1st muhurat (6:00 am to 7:30 pm), 2nd muhurat (7:30 am to 9:00 am), 3rd muhurat (9:00 am to 10:30 am), 4th muhurat (10:30 am to 12:00 pm), 5th muhurat (12:00 pm to 1:30 pm), 6th muhurat (1:30 pm to 3:00 pm), 7th muhurat (3:00 pm to 4:30 pm), 8th muhurat (4:30 pm to 6:00 pm), if the sunrise is 6:00 am and sunset is 6:00 pm.

On Monday, Rahu Kaal falls on 2nd muhurat, Tuesday on 7th muhurat, Wednesday on 5th muhurat, Thursday on 6th muhurat, Friday on 4th muhurat, Saturday on 3rd muhurat and Sunday on 8th muhurat.

To memorise it, read the mnemonic phrase,“Mother Saw Father Wearing The Turban Suddenly” where the first letter of each word indicates the day as per the muhurat.